UTASTAR

Provider:PyXMCDA
Version:1.0

Description

Perform UTASTAR computation on provided inputs. Decision Maker’s Preferences can be provided using either a global ranking of reference alternatives, or the pair-wise alternatives preferences and indifferences. Outputs optimal valueFunctions along their valuesErrors. Can also apply post-optimality analysis for a more balanced output.

The service generate discrete functions for criteria with qualitative scales. Number of segments will be still be used to compute a continuous marginal utility function. It is therefore advised to use (n - 1) as the number of segments (with n the number of labels of the qualitative scale), while using incremented integer values in such scale definition (e.g. { 1, 2, 3,…, n}). Labels of the scale are used as the abscissa.

This service raises an error if the solution found does not give the same ranking of reference alternatives than in inputs (even with application of the values errors, called sigma in (Munda, 2005).

The implementation and indexing conventions are based on:

Munda, G. (2005). UTA Methods. In Multiple criteria decision analysis: State of the art surveys (pp 297-343). Springer, New York, NY.

N.B: This service uses the python module Pulp for representing and solving UTA problems.

Inputs

(For outputs, see below)

alternatives

Optional: yes, enabled by default

Description:

The alternatives. Only used to exclude inactive alternatives from computations (all are considered if not provided).

criteria

Optional: yes, enabled by default

Description:

The criteria. Only used to exclude inactive criteria from computations (all are considered if not provided).

XMCDA related:

  • Tag: criteria

performance table

Description:

The performance table.

XMCDA related:

  • Tag: performanceTable

alternatives preferences

Optional: yes, enabled by default

Description:

The alternatives preferences used to infer utility functions.
If alternatives is provided, all reference alternatives set as inactive are not considered.

XMCDA related:

  • Tag: alternativesMatrix

alternatives indifferences

Optional: yes, enabled by default

Description:

The alternatives indifferences used to infer utility functions.
If alternatives is provided, all reference alternatives set as inactive are not considered.

XMCDA related:

  • Tag: alternativesMatrix

alternatives ranks

Optional: yes, enabled by default

Description:

Ranking of reference alternatives used to infer utility functions.
If alternatives is provided, all reference alternatives set as inactive are not considered.

XMCDA related:

  • Tag: alternativesValues

criteria scales

Optional: yes, enabled by default

Description:

The criteria scales. Mandatory if qualitative values are in performance table.
If not provided, minimum/maximum values will be extracted from performance table, and preference direction will be set to max. Nominal and fuzzy qualitative scales are forbidden.

XMCDA related:

  • Tag: criteriaScales

criteria segments

Description:

Number of segments per marginal utility function.

XMCDA related:

  • Tag: criteriaValues

parameters

Description:

Parameters of the method

GUI information:

  • Parameter values can be defined via the GUI or the XMCDA file, by default via GUI.

  • Name: Inputs alternatives

    How to provide alternatives hierarchy

    • Type: drop-down list
    • Possible values:
      • Use ranking of alternatives (XMCDA label : ranking) (default)
      • Use pairwise preferences and indifferences (XMCDA label : relations)
  • Name: Discrimination threshold

    Discrimination threshold value.

    • Constraint description: Bigger than 0.0.
    • Type: float
    • Default value: 0.001
  • Name: Post optimality

    Post optimality applied or not.

    • Type: drop-down list
    • Possible values:
      • Applied (XMCDA label : true)
      • Not applied (XMCDA label : false) (default)
  • Name: Post-optimality threshold

    Threshold for acceptable solutions used in post-optimality analysis.

    • Constraint description: Bigger or equal to 0.0.
    • Type: float
    • Default value: 0.1
  • Name: Significative figures

    Number of significative figures in outputs values.

    • Constraint description: Bigger than 0.
    • Type: integer
    • Default value: 3
  • Name: Absolute tolerance

    Float absolute tolerance used when computing Kendall tau.

    • Constraint description: Bigger than 0.0.
    • Type: float
    • Default value: 1e-6
  • Name: Solver

    Which solver is used.

    • Type: drop-down list
    • Possible values:
      • Coin-Or CBC (version included in Pulp) (XMCDA label : cbc) (default)
      • Choco (version included in Pulp) (XMCDA label : choco)
      • GLPK (XMCDA label : glpk)

XMCDA related:

  • Tag: programParameters

  • Code:

    <programParameters>
        <!-- %N -->
        <programParameter id="discrimination_threshold" name="Discrimination threshold">
                <values>
                <value>
                            <real>%2</real>
                </value>
                </values>
        </programParameter>
        <programParameter id="post_optimality" name="Post optimality">
                <values>
                <value>
                            <boolean>%1</boolean>
                </value>
                </values>
        </programParameter>%5<programParameter id="significative_figures" name="Significative figures">
                <values>
                <value>
                            <integer>%4</integer>
                </value>
                </values>
        </programParameter>
        <programParameter id="atol" name="Absolute tolerance">
                <values>
                <value>
                            <real>%6</real>
                </value>
                </values>
        </programParameter>
        <programParameter id="solver" name="Solver">
                <values>
                <value>
                            <label>%3</label>
                </value>
                </values>
        </programParameter>
    </programParameters>
    

Outputs

value functions

Description:

Optimal value functions found by the service.

XMCDA related:

  • Tag: criteriaFunctions

values errors

Description:

Optimal values errors found by the service for the reference alternatives.
The 2 values for each alternatives are respectively sigma+ and sigma-. As noted in (Munda, 2005).

XMCDA related:

  • Tag: alternativesValues

messages

Description:

Status messages.

XMCDA related:

  • Tag: programExecutionResult

For further technical details on the web service underlying this program, have a look at its documentation here.